Further development of earwig-safe spray programmes for apple and pear orchards


Project summary:

Earwigs are important generalist predators in both apple and pear orchards. They play a key part in regulating populations of several highly damaging pests including woolly aphid and other aphid pests, mussel scale, codling moth and pear sucker. Recent laboratory tests and field experiments at EMR and on UK growers’ orchards and experiments by other European scientists have indicated that several very commonly used insecticides including thiacloprid (Calypso), indoxacarb (Steward), chlorpyrifos and spinosad (Tracer) have harmful effects on earwigs and could be responsible for the low populations of these important predators in some orchards. However, growers need to be able to use products containing acetamaprid (Gazelle), thiacloprid (Calypso), abamectin (Agrimec) and spirodiclofen (Envidor) for control of aphids, mussel scale, weevils, capsids, pear sucker and sawfly.

This project will build on research carried out by EMR in HDC project TF 196 which showed that earwigs can be disrupted by unsafe crop protection programmes. It will test how to integrate these key pesticides into pest management programmes without causing harm to earwig populations in the orchard. It will further investigate the sub-lethal effects (growth and reproduction) that these pesticides have on nymph and adult earwigs in highly replicated laboratory trials.

Benefits to industry:

• The industry will be provided with independently obtained information on the relative safety of critical orchard insecticides on earwigs; important natural enemies of several damaging pests
• Growers will be able to judge when best to use which insecticides for essential pest control tasks such as control of codling moth, aphids, mussel scale and pear sucker
• There will be less problems with many important pests if earwig populations are allowed to thrive

Project code:
TF 220
01 April 2014 - 31 March 2017
AHDB Horticulture
AHDB sector cost:
Project leader:


TF 220_GS_Final_2017 TF 220_Report_Annual_2016 TF 220_Report_Annual_2015 TF 220_Report_Final_2017 TF 220_GS_Annual_2016 TF 220_GS_Annual_2015

About this project

Aims and objectives:

(i) Project aim:
To determine whether (if and when?) acetamiprid (Gazelle), thiaclorpid (Calypso), abamectin (Agrimec) and spirodiclofen (Envidor) can be used in earwig safe spray programmes on apple and pear
(ii) Project objectives:
1. Determine the effects of acetamaprid (Gazelle), thiacloprid (Calypso), abamectin (Agrimec) and spirodiclofen (Envidor) on the survival, behaviour, growth and reproduction of earwig nymphs and adults in the laboratory (year 1)
2. Evaluate the effects on earwig populations of early season (pre-petal fall) versus mid-season (fruit development) applications of one versus two sprays of acetamaprid (Gazelle) or thiacloprid (Calypso) in apple orchards (year 2).
3. Evaluate the effects on earwig populations of the maximal allowable summer applications of abamectin (Agrimec) or spirodiclofen (Envidor) in pear orchards (year 3).
4. Give recommendations on orchard insecticide application timings to foster earwig-safe spray programmes (year 3)